反应详情

To a flask containing methyl 4-((1S,3aS,5aR,5bR,7aS,9S,11aS,11bR,13aR,13bR)-3a-(chlorocarbonyl)-1-isopropyl-5a,5b,8,8,11a-pentamethylicosahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (77 mg, 0.13 mmol) in DCE (2 mL) was added Hunig'sBase (0.068 mL, 0.390 mmol), DMAP (1 mg, 8.19 μmol), and 2-(2-Aminoethyl)pyridine (0.031 mL, 0.260 mmol). The mixture was stirred for 2.5 hours at rt. The reaction was diluted with 5 mL of water and was extracted with dichloromethane (3×5 mL). The combined organic layers were dried with Na2SO4. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure. The residue was purified by Biotage flash chromatography using a 0-75% ethyl acetate in hexanes gradient. The fractions containing the expected product were combined and concentrated. The expected product, methyl 4-((1S,3aS,5aR,5bR,7aS,9S,11aS,11bR,13aR,13bR)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-3a-(2-(pyridin-2-yl)ethylcarbamoyl)icosahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (0.062 g, 0.091 mmol, 70.0% yield), was isolated as a white foam. LCMS: m/e 679.7 (M−H)−, 3.09 min (method 3).

1. extractionwas extracted with dichloromethane (3×5 mL)
2. dry with materialThe combined organic layers were dried with Na2SO4
3. customThe drying agent was removed by filtration
4. concentrationthe filtrate was concentrated under reduced pressure
5. customThe residue was purified by Biotage flash chromatography
6. additionThe fractions containing the expected product
7. concentrationconcentrated